Insulating glass units, such as double pane and triple pane insulating glass units, are commonly used in windows and doors. The insulating glass units generally have a series of transparent panes separated by gas spaces. For example, a double pane insulating glass unit may have two glass panes separated by a gas space. In order to hold the glass panes apart to provide the gas space, a spacer may be inserted between the two glass panes. The spacer may both hold the glass panes apart from one another and also hermetically seal the gas space created between the panes. The hermetically sealed gas space can be filled with an insulating gas or evacuated to create a vacuum environment, reducing thermal transfer across the gas space and, ultimately, the entire insulating glass unit.
Increased interest in the thermal efficiency of residential and commercial buildings has led to improvements in the thermal insulating properties of insulating glass units. In some new construction applications, triple pane insulating glass units are now used more frequently than double pane insulating glass units. Unlike a double pane insulating glass unit, which generally only has a single gas space positioned between two panes, a triple pane insulating glass unit can provide two separate gas spaces. As a result, a triple pane insulating glass unit can provide better thermal insulation properties than a comparable double pane insulating glass unit, leading to improved thermal efficiencies for the building into which the insulating glass unit is installed.
While a triple pane insulating glass unit can provide better thermal efficiencies than a comparable double pane insulating glass unit, the complexity and reliability of some triple pane designs has limited wide-spread acceptance of the technology to all applications. For example, many window and door frame manufacturers have tooling that is designed to create frames for double pane insulating glass units and cannot accommodate larger triple pane insulating glass units. Likewise, building owners looking to replace existing double pane insulating glass units often end up replacing the exiting units with modern double pane units to avoid the cost of having to rework a window or door opening to accommodate a larger triple pane insulating glass unit. Even when a purchaser decides to use a triple pane unit instead of a double pane unit, the second gas space provided in the triple pane unit can increase the risk of a seal failure if the gas seals for the unit are not properly configured.